1. Field of the Invention
The present invention pertains to the manufacture of flexible packages, such as plastic bags, and in particular to packages having fastener closures employing sliders.
2. Description Of The Related Art
With the recent emphasis in providing consumers with bulk quantities of various commodities, such as food products, reclosable packages have become increasingly popular. One of the most popular means of providing reclosability is to employ zippers of various types, particularly zippers which are compatible with flexible packages of plastic film construction. Manufacturers of food products and other commodities are concerned with filling the contents of a flexible package as quickly and economically as possible. It is important that the opening provided by the fastener be made as large as practically possible. Consumers or other end users also prefer large sized openings for easy extraction of products from the package interior. Even with large openings, however, products within the package may interfere with fastener operation when product poured or otherwise dispensed from the package becomes entrained in the fastener components.
Other improvements to flexible reclosable packages are being sought. For example, when handling products comprised of numerous small pieces, such as shredded cheese or cereal, for example, it is generally desirable to have the package formed into a pouch which is open at one end, or along one side, so as to allow product to be poured or shaken through the reclosable opening. It is desirable that the product be allowed to freely flow past the reclosable opening. Preferably, the path taken by the product within the package should be made as smooth as possible.
Although improvements have been made in the art of plastic welding and joining, manufacturers of consumer products employing high speed production techniques are continually seeking improved package forming methods and equipment.
It is an object of the invention to provide apparatus for manufacturing improved, shrouded and unshrouded flexible packages.
Another object of the invention is to provide apparatus for making reclosable packages having fastener sliders which are protected as the package contents are poured out or otherwise extracted.
A further object of the invention is to provide apparatus for making a reclosable plastic package having a slider fastener with improved containment of the slider in a manner which also optimizes the size of the bag opening.
A further object of the invention is to provide apparatus for making a plastic bag having a slider fastener with an improved end xe2x80x9ccrushxe2x80x9d stop of the fastener tracks.
These and other objects of the invention are attained in a horizontal form-fill seal machine for the in-line manufacturing of food packages with shrouded, mated fastener tracks and slider closures, that comprise a supply of web material that extends in a machine direction that defines a serial succession of package sidewalls and extends in the machine direction. A supply of mated fastener tracks, which include a first track with a shorter flange mated to a second track with a longer flange. A folding member which receives said web material. A web drive that transports said web material over said folding member in the machine direction, folding said web material into overlying side-by-side portions, one against the other, to form a continuous succession of folded package portions, which extend in the machine direction and which have pairs of overlying first and second package sidewalls that have overlying free edges with shroud portions at the free edges. A slider member mateable with said mated fastener tracks for movement along said mated fastener tracks in opposite directions to open and close said mated fastener tracks. A slider installation member that is inserted in the slider member onto said mated fastener tracks. Two pairs of fastener seal bars extend in the machine direction, that seal a portion of each flange of said fastener tracks to said first sidewalls, and leave the flanges free of attachment to the second package sidewalls. Side seal bars extend at an angle to said machine direction, and seal portions of said package sidewalls together to form respective side seals of the food package. A pair of shroud seal bars that extend in the machine direction, and seal the free edges of the package walls to form a closed shroud covering said fastener tracks. A funnel member. A filler member filling product into said package through said funnel. Sidewalls sealing means that seal said second package sidewall to said second track and a shroud sealing member that seals the free edges of said package sidewalls to form a shroud and that closes the fastener tracks, to form a completed food package.